3D pen



FIG. 1 is a front, top perspective view of a 3D pen showing our new design;

FIG. 2 is a rear, bottom perspective view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a front elevational view thereof; and,

FIG. 8 is a rear elevational view thereof.

The broken lines in the Figures show portions of the 3D pen, which form no part of the claimed design. 

CLAIM The ornamental design for a 3D pen, as shown and described. 